Method of making sulfate of copper.



specification.A

The object of my invention is to produce sul- Patented June 28, 1904.

PATENT OFFICE.

GfUsTAVEl GIN, oF PARIS, FRANCE.

I METHOD oF MAKINGSULFATE oF ooPPER.

f sPEciFfI- CATIGN forming part ofneaers Patent No. 763,478, dated Jim@ 28, 1904.

i Application filed July 28,1902. Renewed March 3, 1904. Serial No. 196,322. (No specimens.)

10 all whom iii-may can/cern:

France, have invented a certain new and useful Improvement in the Manufacture ofSulfate of Copper, of which the following is a fate-of-copper crystals free from impurities, particularly from sulfate of iron. For this purpose I use sulfurous ores or mattes of copper in which the suliids of copper and of iron have been previously transformed into sulfates by any known means.

lAlthough I have adoptedY purely physical quite different from those which correspond to the solution of either -sulfate alone. The solubility of ferrous sulfate grows at first with the rising temperature more rapidly than that of the copper sulfate; but when the solution is heated above 100G-the respective solubilities again follow thelaw governing solutions ofthe isolated salts, so that at about 160O centigrade sulfate of `copper alone remains in the solution, while the ferrous Ysulfate is entirely precipitated. My process is deducted from these observations and 'is carried out in the following manner: The ores or mattes from which it is proposed to extract the sulfate of copper are rst subjected to any known treatment which will transform the metallic sulfids present into sulfates. I then take these compound sulfates, there 'being present copper sulfate, with a certain proportion of ferric and ferrous sulfates, and I lixiviate them, so as to obtain saturated solutions of sulfates as hot as possible. I then boil them with copper ore which has been completely oxidized by high roasting or with @mentation-copper.

The4 sulfate of peroxid of iron reacts upon the The sulfate of peroxid of iron remains untouched in the solution. The solution is maintained at about a boiling temperature and is th en filtered. containing after filtration sulfate of copper and sulfate of protoxid of iron only. It is then injected by any suitable means into a copper boiler, preferably of the tubular variety, in which it is heated until the gage indicates a pressure of ten kilos, which corresponds to a temperature of about 180O centigrade. At this temperature the sulfate of protoxid of iron can no longer exist in the solution; but the copper sulfate is still very soluble. I preferably use concentrated solutions;

but this concentration should not reach the A maximum saturation of copper sulfate, for a certain quantityof this salt would be precipitated with the sulfate of protoxid of iron. I have found that a concentration of three hundred and-fifty to four hundred grams of copper sulfate per litre of solution is favorable to the proper separation. The pressure exerted upon the solution in the boiler is used to force it into a lter-press, the compartments or arrangement which may cause this separation ina practical manner.

Figure l is a practical elevation of the appal ratus. Fig. 2 is a plan view. Fig; Sis a crosssection through a single plate;v Fig. l is a longitudinal section through-three plates.

, The turbid solution enters the apparatus through a pipe A and passes into the chambers B. It is filtered through asbestos screens C, and all the sulfate of iron which is in sus- IOO .pension is left between the asbestos screens,

heated by means of steam at a pressure of tenf kilograms. It enters the apparatus at F and circulates from one chamber to the other by means of the U-shaped pipes L, making its escape at Gr. The chambers of the filter-press are formed by bronze frames H, closed by the plates or diaphragms L, braced by short stays K. When the spaces between the filterscreens are filled with the precipitated sulfate of iron, the supply-valve N is closed and the circulation of steam through the compartments is stopped. The incoming vstream of 'the solution to be filtered is then directed to an additional filter-press, while pure water is applied to the iirst apparatus in use through the valve N,.whereby the sulfate of iron is rapidly dissolved. The solution thus obtained is ledto. a special vessel for crystallization. As the filter-press has thus been perfectly cleaned, it may be used immediately for another operation, and thus the operation is rendered continuous by alternately using and cleaning each of the two filter-presses. It may also be remarked that as the filter-press is cleaned by simply washing it with water there will be no occasion for taking it apart except to replace defective asbestos screens'.

What Iclaim is The herein -described process of manufacturing sulfate of copper consisting in boiling a mixed solution containing sulfate of copper, sulfate oi' protoXid ot' iron and sulfate of peroXid of iron with thoroughly-roasted copper ore or cementation-copper so that the peroxid contained in the sulfate of peroxid of iron will first be precipitated` then precipitating the sulfate of protoxid of iron remaining in the solution by raising the temperature to a point above 160O centgrade, and then liltering the solution.

In testimony whereof I have hereunto set my hand in presence of two witnesses.

GUSTAVE G1 N.

Witnesses:

ADOLPHE STURM, vEDWARD P. MGLEAN. 

